The Truth About Bike Tire Valve Caps

As keen cyclists, we’ve probably all been here before. You go to pump up your tires to notice that your pesky valve cap is missing. It leaves you wondering how and where it fell off.

Did you not screw it on enough last time or maybe you forgot to put it back on the last time you put air in your tires. Either way, this situation often leaves us with a lot of questions. 

The most common question you may find yourself asking is will my tires deflate without a valve cap? In this article, we want to get to the bottom of this question and answer any other truths about tire valve caps that you may not be aware of.

If you’ve just lost a valve cap or just want to know what to do if you do, then be sure to read on. 

Without any further ado, let’s get stuck into the article.  

Will Your Bike Tire Deflate Without A Valve Cap?

To put it simply, no, your bike tire will not lose air or deflate if the valve caps are missing. While they are important to your bike they don’t actually hold in air at all.

The valve caps primary and most important function is to keep the valve on your wheel dirt-free. 

Officially valve caps are actually called “valve stem caps”. The cap’s function is to cover the tire valve to assist in keeping it clean.

Dirt and grime can easily build up around the valve on your wheel, especially if you prefer off-road riding. If it wasn’t for the valve caps your tire valve would get ruined surprisingly quickly.

As well as dirt getting into your valve you may also encounter corrosion and leaking. As more dust builds up around the valve it is possible for it to cause damage to your bike and cause the valve to leak. 

If you want to give more life to your tire tubes and ensure they don’t get worn away too quickly always make sure you have two valve caps on your bike.  

Can You Still Ride Your Bike Without A Valve Cap?

You can still ride your bike if it doesn’t have a cap on the tire stem. It won’t affect your riding performance or impact the air pressure in your tire.

You could potentially ride hundreds of miles without a valve stem cap on whether you knew it was missing or not. Despite this, it is strongly recommended that if you notice your tire valve cap missing, you should replace it as soon as you can.

Replacing the missing cap as quickly as you can will reduce the risk of any dirt or dust getting into your valve causing the problems we spoke about earlier.

Why Does My Tire Still Leak?

It is an old cycling myth that tire caps keep air locked into the tire tubes, so what causes your tire to still leak air. If your tire doesn’t have a cap then it could be that dirt happened to make its way inside the valve.

There is another explanation though if your bike does have both tire valve caps. 

Depending on the age of your tire and how much you use your bike natural deflation could take place. Over time your tires will generally start to deflate and become worn out.

This is completely normal and doesn’t relate to how you ride the bike. When your tire starts to wear down or deflate it could be time to purchase a new tire tube. 

Types Of Valve Caps

You may or may not be aware that valve stem caps vary depending on the type of bike you ride. Road bikes and a small number of hybrids have Presta valves.

This valve is a thin, narrow tube that has a metal screw feature that ensures the valve is shut. The most important part of this valve is making sure the screw is shut properly.

The cap on this valve cap protects the valve from oxidation and grime whilst also preventing the stem from getting bent as you ride. 

Mountain bikes, most hybrids, and cruisers are fitted with a Schrader valve. The Schrader valve is basically a tube with a flap that holds against air pressure.

The cap keeps dirt and grime out of the flap. If dirt was to find its way in the valve wouldn’t work. This could result in the need to replace the entire bike tube. 

Where Do Missing Bike Tire Valve Caps Go?

We are sure valve caps have a life of their own. They are just one of those objects that seem to vanish into thin air. There’s a good chance they are with your other missing household items.

No, but in all seriousness, there isn’t a way of being able to work out where tire valve caps go unless you happen to stumble across it.

The most obvious explanation is that it fell off as you were riding or you forgot to put it back on and lost it. 

It is worth noting that a lost tire cap whilst riding is easily done. It doesn’t mean you are riding incorrectly or there is a problem with your tires. Sometimes things like this just happen. 

Buying New Valve Caps

If you’re unfortunate enough to lose a tire cap then you will want to buy a new one pretty quickly. Amazon is normally an excellent place to buy new tire caps because there are plenty to choose from and they can arrive the next day thanks to next-day delivery.

You can buy valve caps in many different styles and designs depending on what you are looking for. 

We quite like the idea of making our bikes look better with some colorful caps that give our bikes good protection and that extra decorative edge.

You can buy a 10 pack of Presta Valves on Amazon that all come in different colors. If you’re wanting some valve caps that work well and give your bike some more color then check them out. 

The advantage to buying a bigger pack of valve caps is that you are prepared for the next time a cap goes missing, and let’s face it that will probably happen at some point. 


So a missing valve cap doesn’t impact the air pressure in your tire. This is just an old cycling legend. They are, however, still important to the general health of our bike’s tires.

Without a valve cap, a tire’s valve could potentially be damaged or start to leak as a result of a build-up of dirt, grime, and dust.

If you do lose a valve cap you should always try to replace it as soon as you can. If you choose not to, your cycling performance will not suffer and there is a high chance your tires will be fine.

However, by riding without a valve cap you will always run the risk of damaging the tire. 

We have gone through a lot in this article but unfortunately, we still can’t tell you where on earth those dastardly missing valve caps go. You might have to work that one out yourself.

Andrew Daniels